Personally, I prefer the non-carbon type. I'm currently in a Specialized Taho. It has more of a traditional sneaker-like "tacky" sole. I've had very bad experiences losing traction when putting a foot down with stiff/hard soled MTB shoes. They can be very skittery for hike-a-bike on rocky terrain, and they slip when walking on Anything but dirt. For hot feet, you might look into improving the fit with a footbed.